Input on heads/cam for TSP 421 cu in.
Input on heads/cam for TSP 421 cu in. Right now im at the stage of planning my next big build. Right now my setup is TFS 215, vindicator cam, 90/90 fast setup with a stock buttom end. I know im going with a custom grind prolly from TSP also. So ive been looking at the 421 TSP short block, custom grind cam, and i having trouble which heads to go with. I looked at the flow no# on the L92 heads and the TFS 235's and the L92 flow better(TEA website bench numbers). But overall which is a better pair of heads and help maximize the block the engine. It'll be a N/A motor with possibly 150-200 shot of nitrous too. If i can save $500-800 that would be great!! IF there are other choices out there plz give me some input. It'll be a street car not much track time. Also should i just keep the fast 90mm intake? is it worth to spend the money for a 102mm? I'll appreciate all the help.
If you go with the l92s you have to get different rockers, different intake, and different injectors. If you stay cathedral port you can re-use your intake, your rockers, and your injectors possibly.
thats fine i dont mind. i just need to know which heads i would get better performance with. on the TEA website they have a pair of l92's that flow really good and under $2k. but will they perform better than the TFS 235's?
yeah i asked that question to TEA and they said it'll better if i just pick up a set of 235's. then i looked into their website and saw their stg 2 L92 heads and its $500-600 cheaper. i can maybe use it to buy a new intake manifold if its worth it.
BTW my goal is to reach 600rwhp N/A if possible if not very close to it. But drive it on the street. Driveability is not much of an issue. Its going to be a weekend warrior
Not too many hit 600rwhp NA without very high compression and a monster cam. But TFS 235s would be my choice. They consisently make 540-550rwhp. I havent seen any other head as consisnt as the TFS 235s.
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go with the TFS 235 heads. I had a set on my Tick Performance built 423 ci motor and it made 544 rwhp through a th350,4000 nitrous stall,steel drive shaft,12 bolt w/ 4.10's. With a m6 it would be all over 590 rwhp. It was about 11.75-12.1 compression and it had a .647-.647 lift hydraulic cam. They are a bad *** head for sure.
Don't forget the PRC 237 heads, checkout the hot rod magazine shootout with all the cathedral heads. The PRC 237 heads moved the most air & are on special pricing. 
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Well my vote is for the 235's. I made 550 with a small 244/246 615 lift cam through the 90/90 with a 85mm maf. At the time that the car was dynoed the tuner felt that there was more in the motor that the 85mm maf was restricting.
Have switched to a 102/102 and am working on a SD tune. If you are able to tune your own car then I would go SD with the 90/90 to see the results. If it doesn't work out you can always sell the 90/90 and move up to a ported 102.
The car was dynoed with the steel driveshaft through the 9" rear. All accessories attached.
Have switched to a 102/102 and am working on a SD tune. If you are able to tune your own car then I would go SD with the 90/90 to see the results. If it doesn't work out you can always sell the 90/90 and move up to a ported 102.
The car was dynoed with the steel driveshaft through the 9" rear. All accessories attached.
With all the mods in my sig ill be happy with 550, but I'm hoping for more. I bought my Ls3 heads from LPE and everyone including AES said they did a nice job reshaping the intake port and the cnc job in awesome too! And I also compared the flow numbers and there wasn't much difference. Plus they come with springs and they mill for free too. They cost me 1600 shipped.
So I say go 102 and don't look back.
Sounds like you got a winner!
So I say go 102 and don't look back.
Sounds like you got a winner!
TECH Enthusiast
Joined: May 2008
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Your best bet for 600+ rwhp is going to be to go to 4.125 bore and LS7 style heads on a 427 or 440 - more money but a proven approach to high levels of na power.
For the 416, also look at WCCH L92 heads or MAST LS3 offerings. More money again but better excellent reputation and flow numbers. Watch flow numbers from suppliers - not everyone uses the same bore size and this can skew the values.
For the 416, also look at WCCH L92 heads or MAST LS3 offerings. More money again but better excellent reputation and flow numbers. Watch flow numbers from suppliers - not everyone uses the same bore size and this can skew the values.
